def test_not_all_used(self):
        fmt = "The value of x is %(x)s"
        text = format(fmt,x=3,y=5)
        self.assertEqual(text,"""\
The value of x is 3
Additional arguments:
y = 5
""")        
    def test_unknown(self):
        fmt = "The value of x is %(z)s"
        text = format(fmt,x=3,y=5)
        self.assertEqual(text,"""\
The value of x is <UNKNOWN PARAMETER z>
Additional arguments:
x = 3
y = 5
""")        
    def test_all_used(self):
        fmt = """\
The value of x is %(x)s.
And y is %(y)s!
"""        
        text = format(fmt,x=3,y=5)
        self.assertEqual(text,"""\
The value of x is 3.
And y is 5!
""")